The finite element theory, in conjunction with Galerkin's residual method, was used to mathematically route overland and channel flow. This numerical procedure was applied to the kinematic equations of one-dimensional transient flow in open channels. A one-dimensional finite element scheme was used to simulate overland flow over the watershed and open channel flow in the main streams, after a finite element grid had been devised for both the watershed and the streams. Rainfall excess, the major input parameter, was obtained as a function of rainfall, depending on soil properties and existing land-use conditions across the watershed, The model was tested and calibrated on a natural watershed, The nature of the finite element procedure allowed changes in land-use to be easily incorporated into the model. The effect of several arbitrary land-use changes upon the response of the river under flood conditions was observed. The effect of changes in the number and size of the elements in the watershed and the streams was also observed along with changes in the size of the time increment. / M. S.

Extracurricular programs have been a part of the public schools since the early 1800's. By the middle of the twentieth century the number and diversity of extracurricular activities increased appreciably. As school activities have increased the supportive funds necessary to finance these programs have increased proportionately. As often happens in areas of rapid growth, administrative policies and procedures designed to operate the programs have tended not to keep pace with the expanding program structure. The rapid growth of extracurricular programs in recent years has placed strain on the now obsolete financial system with which the financial administrators have had to content. The Manual on System of Accounting for Student Activity Funds currently in use in Virginia Public Schools was adopted in 1954. The problem of this study was to design a current, legally based, and theoretically and operationally sound manual of accounting for school activity funds in the state of Virginia. More specifically, the problem of this study was to synthesize empirically-based information into a user-adjudged feasible and desirable policy and procedure statement which would provide the practicing school administrator with a comprehensive document for accounting for school activity funds. From a study of the literature in the area of student activity fund accounting, an examination of case and statutory law from across the United States, a review of Virginia School Laws, Regulations of the State Board of Education, Virginia Attorney Generals Opinions, and the expertise provided by certified public accountants, high school principals and high school bookkeepers, a manual for accounting for student activity funds was developed. This manual reflects the best judgment of a user audience concerning the current state of the art of the management of student activity funds, and contains explanations and instructions essential to the administration of and accounting for student activity funds. Section titles of the manual as developed were as follows: Section I: Virginia State Laws and State Board Regulations Section II: Classification of Receipts and Expenditures Section III: Accounting Procedures Section IV: Internal Control Section V: Management of Student Body Funds Section VI: Responsibilities of Personnel in Student Activity Fund Accounting Section VII: Approved Forms and Instructions Section VIII: Glossary of Terms / Ed. D.

An economical process for the elimination of nutrients to receiving waters.is a major problem now facing modern wastewater treatment. The purpose of this investigation was to determine the feasibility of soluble phosphate removal in a flyash contact system. The investigation consisted of experiments involving batch adsorption studies and continuous flow studies. Removal kinetics and relationships between contact time, “t” , and flyash concentration, “D_f”, were evaluated using batch adsorption techniques. Of the two flyash samples tested the high alumina content flyash exhibited the best rate of phosphate removal. The high alumina content flyash yielded an average removal capacity of 2.47 x l0⁻⁴ grams of phosphorus per gram of flyash, whereas the low alumina content flyash yielded an average capacity of only 1.61 x 10⁻⁴ grams of phosphorus per gram of flyash. Continuous flow operations were conducted using both types of flyash so as to observe the removal in an actual process situation. The phosphate removal was concluded to be both physical and chemical in nature, with two removal mechanisms predominating. The primary physical mechanism involved the phosphate adsorption on the alumina surface found in the flyash. The chemical removal mechanism was postulated to be the precipitation of phosphate as Mg₃(PO₄)₂ and Ca₃(PO₄)₂ at pH levels above 8.0. / Master of Science

Air drying of naturally infested soils (0.12 to 0.38% water or about -2,000 bars) resulted in no recovery of Cylindrocladium crotalariae microsclerotia, but rewetting soils to near field capacity for 1 to 4 wk before assay resulted in partial recovery from the air drying-induced decreased germinability. Numbers of germinable C. crotalariae microsclerotia (assayed at 26 C) decreased progressively over 4 wk when naturally infested soils were incubated at 6 C. No germinable microsclerotia were recovered when soils were incubated at -10 C. When soils incubated at -10 C and at 6 C were transferred to 26 C for 4 wk, the low-temperature effect was partially reversed. Incubation of naturally infested soils under field conditions over the winter months (November-February) indicated that a similar low-temperature phenomenon exists in nature. Germinability of axenic, laboratory-grown microsclerotia of C. crotalariae, C. floridanum, and C. scoparium incubated 4 wk at 6 C ranged from 0 to 91.3% (mean = 37.7%) of the initial germinability. Partial recovery of laboratory-grown microsclerotia from the lowtemperature effect, by incubation at 26 C, was demonstrated. Conductivity measurements of solutions bathing microsclerotia incubated at 6 C and 26 C for 4 wk indicated that chilling injury may account, in part, for decreased germinability of microsclerotia. Direct observation of washed conidia of C. scoparium on rewetted, non-sterile soils at 26 C indicated that peak germination (33-58%) occurred after 24 h incubation. Peak germination on continually moist soils was somewhat lower (18-26%) than on rewetted soils. Conidia did not germinate on continually moist soils at 6 C. Conidia germinated at a high level (93-95%) in axenic culture in the absence of exogenous carbon and nitrogen substrates. The inhibition of conidium germination on soils was due, in part, to the presence of fungistatic soil volatiles. Addition of low levels of carbon and nitrogen substrates nullified the inhibitory effect of soil volatiles. Germinability of C. scoparium, C. crotalariae, and C. floridanum conidia in artificially infested soils (assayed on a selective medium at 26 C) decreased progressively during incubation at 26 C from 1 wk to 4 mo. No germinable conidia were recovered after incubation of soils at 6 C for 4 wk. Control of Cylindrocladium root rot of black wainut seedlings with sodium azide at 224 kg/ha applied by the plowdown method was comparable to MC-33 at 504 kg/ha. Sodium azide at 67 kg/ha was only marginally effective in disease control. Reduction of Cylindrocladium microsclerotium populations, qualitatively assayed by the azalea leaftrap method, was found in soil samples from plots fumigated with sodium azide and MC-33. A small-spored Cylindrocladium sp. with clavate to papillate vesicles, identified as C. parvum, was consistently recovered from diseased roots and soil samples from a Virginia forest nursery. Percentage recovery from necrotic roots and soil samples collected from root zones of necrotic black walnut seedlings was appreciably higher for C. parvum than for C. floridanum or C. scoparium. In greenhouse tests, limited pathogenicity of C. parvum on black walnut seedlings was demonstrated. / Ph. D.

The effects of contaminated supply air on the performance of a laminar proportional amplifier were experimentally investigated. The air supply was contaminated with oil vapor and particulate matter. Characteristic gain curves were obtained after each stage of contamination for various loading conditions. Photographs showing the location of contaminant deposits were taken. Two inlet geometries were studied: right-angle and straightthrough. The effects of maintaining a constant pressure and constant flow rate at the inlet throughout the duration of the tests were studied. Also, aspect ratio effects. were studied. Rapid deterioration of performance was evident with the right-angle entry due to inlet blockage. By milling a cavity in the bottom cover plate, the detrimental effects of inlet blockage were delayed. With constant pressure inlet conditions and straight-through geometry, significant buildup occurred in the nozzle region and downstream. Decrease in pressure recovery was linear with time. It was determined that null shift was caused by asymmetric buildup in either the nozzle region or splitter region. With constant flow inlet conditions, the damaging effects on performance were delayed for both inlet geometries. Also, for the straight-through inlet, the nozzle region was relatively clean when compared with the constant pressure inlet case. Null shift was found to be the result of asymmetric buildup in the downstream region. At lower aspect ratios, the damaging effects of contamination were more severe and occurred in less time. / Master of Science